A HOODLUM is a thug , usually in a group of misfits who are
associated with crime or theft. The earliest reference to the word
hoodlum was in the December 14, 1866 San Francisco Daily Evening
Bulletin, after the
Hoodlum Band was arrested on December 13, 1866.
Members of the gang were sentenced to the Industrial School for
stealing clothes. The gang used many keys to enter hotel rooms and
boarding houses. On December 14, 1866, Lazarus Moses was arrested for
selling clothes stolen by the
Hoodlum Band. Mr. Moses was fined $300.
Mr. Moses' nickname was
Fagin . The public read about the acts of the
Hoodlum Band, and the word hoodlum became a synonym for a young thug.

An article in the New York Times of July 26, 1877 included this: "…
People who sack Chinese houses and stone Chinamen are not workingmen.
San Francisco calls them ‘hoodlums,’ a term which includes
everything that is base and mean. The hoodlum is a non-producer,
loafer and bully. The hoodlum class think this is a good time to
signify their hatred of law and order."